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journal article 2009
Novel microsatellite loci for the Burrowing Owl Athene cunicularia
Lead author: Alberto Macias-Duarte
The breeding distribution of western burrowing owl is experiencing an intriguing southward shift, contrary to the predictions of climate change. To determine the breeding dispersal patterns underlying this distributional change, we developed 11 novel polymorphic microsatellite loci for the species. We tested these loci in two burrowing owl breeding populations, one from central Sinaloa, Mexico, and one from the Central Valley of California, USA. All loci were at Hardy-Weinberg equilibrium, except two loci for the California population. Expected heterozygosity was relatively high (HE = 0.813, range 0.515-0.942). Average number of alleles was 11.64 (range 5-25). We found no evidence of linkage disequilibrium for any pairwise tests between loci.

powerpoint presentation 2021
Western Burrowing Owl Genomics
Lead author: Kelly Barr
Presentation at the December 6, 2021 burrowing owl annual meeting.

report 2003
Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States
Lead author: Loren W. Ayers
The Western Burrowing Owl (Athene cunicularia hypugaea) is a grassland specialist distributed throughout w. North America, primarily in open areas with short vegetation and bare ground in desert, grassland, and shrub-steppe environments. Burrowing Owls are dependent on the presence of fossorial mammals (primarily prairie dogs and ground squirrels), whose burrows are used for nesting and roosting. Burrowing Owls are protected by the Migratory Bird Treaty Act in the United States and Mexico. They are listed as Endangered in Canada and Threatened in Mexico. They are considered by the U.S. Fish and Wildlife Service (USFWS) to be a Bird of Conservation Concern at the national level, in three USFWS regions, and in nine Bird Conservation Regions . At the state level, Burrowing Owls are listed as Endangered in Minnesota, Threatened in Colorado, and as a Species of Concern in California, Montana, Oklahoma, Oregon, Utah, Washington, and Wyoming. Burrowing Owls historically bred from sc. and sw. Canada southward through the Great Plains and w. United States and south to c. Mexico. Although the historical breeding range is largely intact, range contractions have occurred primarily at peripheral regions, in s. Canada, the ne. Great Plains, and parts of California and the Pacific Northwest. Burrowing Owls winter in the sw. and sc. United States, throughout Mexico, and occasionally as far south as Panama. Populations of Burrowing Owls have declined in several large regions, notably in the ne. Great Plains and Canada. However, estimates of population trends in many regions are generally inconclusive due to small samples sizes and high data variability. Population trends as determined from North American Breeding Bird Survey (BBS) data were inconsistent, with some regions exhibiting positive trends and other regions exhibiting negative trends. When taken as a whole, the BBS indicated an area of generally declining populations in the northern half of the Great Plains, and generally increasing populations in the interior U.S. and in some southwestern deserts. The Christmas Bird Count indicated a significant population decline in California (1966-1989). Local surveys have detected declining populations and/or range reductions in California, Iowa, Kansas, Minnesota, Nebraska, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Washington, and throughout the range of the species in Canada. Primary threats across th

report 2020
Final Report: Vernal Pool Habitat Restoration at Otay Mesa Open Space
The Spring Canyon/Goat Mesa vernal pools complex (J16-18) were identified by the adopted Recovery Plan for Vernal Pools of Southern California (USFWS 1998) as necessary to stabilize populations of the following endangered and threatened species: E. aristulatum, P. nudiuscula, N. fossalis, O. californica, B. sandiegonensis, and S. woottoni. The Management Strategic Plan for Conserved Lands in Western San Diego County (SDMMP) also lists other MSP species historically found onsite at Spring Canyon/Goat Mesa including D. variagata, M. minimus, S. hammondii, and A. cunicularia. Otay Mesa/Goat Mesa Open Space has also had recent recorded occurrences of Western Burrowing Owl, including a pair of owls observed using artificial burrows as recently as December 29, 2017 before the grant project started.

report 2015
Project Report 2015 An adaptive management approach to recovering burrowing owl populations and restoring a grassland ecosystem in San Diego County
Lead author: Sarah McCullough Hennessy
We report on the fifth year’s progress in a multi-year program with the goal of developing a strategy to support the recovery of Western burrowing owls (BUOW; Athene cunicularia hypugaea) and their grassland ecosystem in San Diego County. Current BUOW management is dependent on continued human intervention and may not be self-sustaining. Because the California ground squirrel (Otospermophilus beecheyi) is a keystone species that helps engineer California grassland ecosystems and provides critical resources for BUOW, re-establishment of this species is a crucial component of any sustainable recovery plan for BUOW and the larger ecosystem. The main components of the program in 2015 consisted of work on both BUOW and California ground squirrel. For squirrels, we continued monitoring two previously established studies: (1) the experimental manipulation of grassland habitat structure and squirrel translocation to better support the persistence of ground squirrels, and (2) a pilot manipulation of natural squirrel dispersal into newly grazed pasture, using the addition of cover piles to attract squirrels into unoccupied habitat. In 2015, BUOW efforts continued to focus on understanding the ecological drivers and anthropogenic threats influencing BUOW population performance in San Diego County, as well as development of a new habitat suitability model for BUOW. These efforts were conducted collaboratively with California Department of Fish and Wildlife, San Diego Management and Monitoring Program, and other agency partners.

report 2013
An adaptive management approach to recovering burrowing owl populations and restoring a grassland ecosystem in San Diego County, Project Report 2013
We report on the third year's progress in a multi-year program with the goal of developing a model program to assist with the recovery of Western burrowing owls (BUOW; Athene cunicularia hypugaea) and their grassland ecosystem in San Diego County. Current BUOW management is dependent on continued human intervention and may not be self-sustaining. Because the California ground squirrel (Otospermophilus beecheyi) is a keystone species that helps engineer California grassland ecosystems and provides critical resources for BUOW, re-establishment of this species is a crucial component of any sustainable recovery plan for BUOW and the larger ecosystem. Over time we plan to develop a set of protocols and strategies that can be adopted by managers in San Diego County and in other areas where BUOW conservation management is warranted. Our long-term goal is to assist in the establishment of a more natural grassland ecosystem in San Diego County by re-establishing ground squirrels and, ultimately BUOW. The work described here is the projection of the San Diego Zoo Institute for Conservation Research (ICR) and its partners, in particular, its research collaborators at San Diego State University. In 2013, we made progress towards three objectives: 1) use of translocation as a tool to establish California ground squirrels as ecosystem engineers, 2) developing methodology for monitoring natural squirrel dispersal into managed habitat at Rancho Jamul, 3) determining key habitat associations for California ground squirrels, and 4) monitoring BUOW population and nesting ecology in south San Diego County.